Method of using cosmetic compositions comprising an extract of eclipta alba

ABSTRACT

Cosmetic composition for the regulation of skin pigmentation, comprising wedelolactone an/or desmethylwedelactone or an extract of Eclipta alba.

FIELD OF THE INVENTION

The invention relates to new cosmetic compositions which allow theregulation of cutaneous pigmentation.

BACKGROUND OF THE INVENTION

Irregularities in the pigmentation of the skin have always beenconsidered unsightly, and for some considerable time various means havebeen proposed to remedy this.

These defects appear most often in the form of hyperpigmentationblemishes, which may take diverse forms: freckles, chloasma of hormonalorigin, senile lentigo located mainly on the hands, hyperpigmentationrelated to scars or resulting from a photosensitizing agent, and thelike.

A most diverse range of approaches has been proposed for removing theseblemishes, and whitening the skin, imparting a uniform colorationthereto. The use of numerous substances of animal or mineral origin, aswell as of a large variety of plants and substances of vegetable origin,has been recommended for this purpose. The publication of SCARPA andGUERCI [Journal of Ethnopharmacology, 19 17-66 (1987)] reveals thediversity of the preparations proposed.

However, a very small number of the formulations thus proposed haveshown any real proof of their effectiveness. At the present time, veryfew substances are known which have a real depigmenting effect, andamong these substances the majority exhibit annoying, or even harmful,side effects.

For example, certain preparations based on mercury salts, althoughendowed with a real power for lightening the skin, present real danger,because the transcutaneously absorbed mercury may cause seriouspoisoning.

The majority of the depigmenting preparations currently availablecommercially contain hydroquinone as the active ingredient. Thesepreparations are, however, not without disadvantages. They are in factvery difficult to handle: their application must effectively be strictlylimited to the regions to be depigmented, and the amount used must becarefully dosed. These disadvantages are particularly important forsubjects of dark skin, for whom there is a risk of new blemishesappearing resulting from a non-uniform depigmentation. In addition,hydroquinone is poorly tolerated by many people, in whom it provokesskin irritations.

Among the innumerable active principles of vegetable origin, orextracted from plants, to which a depigmenting action has beenattributed, only one is effectively used in cosmetology: this is anextract of the common yarrow, whose activity is thought to arise fromthe presence of luteolin and its heterosides.

The Inventor has undertaken research with the aim of discovering othersubstances which regulate pigmentation without, however, exhibiting thedisadvantages of the substances currently used.

It is in fact desirable to have available substances which removepigmentation blemishes without, however, provoking a general whiteningof the skin or else an excessive depigmentation of the regions treated.It is in addition necessary for these active principles to be welltolerated and, in particular, not to provoke irritation.

SUMMARY OF THE INVENTION

Now, the Inventor found that extracts obtained from the plant Ecliptaalba possessed depigmenting properties, without provoking the sideeffects mentioned above. By fractionating the extracts obtained, theInventor additionally found that these properties were associated withthe fraction of the plant which is rich in flavonoids, and thatpreparations containing wedelolactone or demethylwedelolactone, whichare the main flavonoids of Eclipta alba, also possessed depigmentingproperties.

Eclipta alba is a plant which belongs to the family Compositae, andwhich is frequently encountered in tropical regions (India, Africa, WestIndies, Guyana). This plant has been the subject of diverse studieswhich have resulted in the discovery of various active principles. ThusBHARGAVA et al. [Indian Journal of Chemistry, 10 810-811 (1972)]extracted 3 isoflavonoids from the leaves: wedelolactone,demethylwedelolactone and its glucoside. QUISUMBING [Medicinal Plants ofthe Philippines: Technical Bulletin--Department of Agriculture andNatural Resources--Republic of the Philippines, Manila; 16, 1234 (1951)]discovered resins, as well as an alkaloid: ecliptine. KARRER[Konstitution und Vorkommen der Organischen Pflanzenstoffe, Birkh auserVerlag--Basle and Stuttgart, 1st Vol. p. 1207, (1958); Supplement I p.1038, (1977); Supplement II p. 939, (1981)] described the presence of asterol: stigmasterol. HEYWOOD et al. [The Biology and Chemistry of theCompositae--Academic Press, London (1977)] mentioned that the aerialparts contained nicotine.

Conventional medicine has proposed various uses for Eclipta alba; inparticular, in the West Indies, the crushed roots have been used as ananti-haemorrhagic agent, as well as in the treatment of leprosy. Somestudies have led to an anti-viral activity being attributed to thisplant [DHAR et al., Indian J. Exp. Biology, 232-247 (1968)], and morerecently, some in vitro anti-bacterial activity [PHADKE S. A., Indian J.Med. Sci. 43:(5), 113-117, (1989)]. A review of the various known useshas been published by H. M. BURKILL ["The Useful Plants of West TropicalAfrica", Vol. 1, 466-468, Royal Botanic Gardens, Kew, (1985)].

However, hitherto, no activity of Eclipta alba on skin pigmentationdefects has been shown.

The present invention relates to cosmetic compositions for theregulation of cutaneous pigmentation, characterized in that theycomprise, as active principle, wedelolactone and/ordemethylwedelolactone.

According to a preferred embodiment of the cosmetic compositionsaccording to the invention, they comprise between 0.1 and 15% by weightof wedelolactone and/or between 0.1 and 15% by weight ofdemethylwedelolactone.

Compositions containing low doses (less than 0.5% of each of the activeprinciples) will preferably be used preventively, or in a maintenancetreatment. Compositions containing higher doses (between 0.5 and 2%)will preferably be used for the treatment of pigmentation defects whichare already established. The compositions containing the highest doses(more than 2%) will be preferred for vigorous treatments, in particularin the case of long-established pigmentation irregularities. In somespecial cases, compositions containing even higher doses may be readilyused, by virtue of the excellent tolerability of these activeprinciples. Thus, the Inventor has successfully tested a concentratedaqueous alcoholic extract of Eclipta alba comprising 10% ofdemethylwedelolactone and 7% of wedelolactone, without observing anyside effects other than a slight drying of the skin, attributable to thealcohol content of the extract.

According to a preferred embodiment of the cosmetic compositionsaccording to the invention, the said active principle is present in theform of an extract of plants which are rich in wedelolactone and/or indemethylwedelolactone.

The presence of wedelolactone and demethylwedelolactone in largequantities has been described for various plants, belonging particularlyto the family Composite, for example Wedelia; extracts of these plantscan consequently be employed to obtain compositions in accordance withthe invention; however, in the course of experiments carried out by theInventor, the best results were obtained using an extract of Ecliptaalba.

According to a preferred arrangement of this embodiment, the saidvegetable extract is an extract of Eclipta alba; advantageously, it isan extract enriched in flavonoids.

An extract enriched in flavonoids is, for example, an aqueous-alcoholicextract obtained from leaves of Eclipta alba, which may be concentrated,so as to contain preferably between 5 and 25% by weight ofdemethylwedelolactone and between 2 and 15% by weight of wedelolactone.

Advantageously, the cosmetic compositions according to the inventioncomprise between 1 and 25% by weight of aqueous alcoholic extract ofleaves of Eclipta alba.

The extract of Eclipta alba can be combined with various excipients, aswell as with other active principles known per se, to obtainpreparations which are suited to different skin types and which are ablewhere appropriate to combine the depigmenting action with anothertreating action (moisturizing agents, anti-wrinkle agents, emollients,anti-seborrhoeic agents, and the like).

The cosmetic preparations according to the invention are particularlyeffective on brown or black melanin-based hyperpigmentations related toscars or resulting from a photosensitizing agent, as well as on thehyperpigmentations of senile lentigo.

Advantageously, to obtain cosmetic preparations more particularlyintended for the treatment of freckles one hormonal hyperpigmentations(chloasma), an extract of Betula alba is combined with the compositionsaccording to the invention.

The silver birch (Betula alba) is among the plants which aretraditionally recommended for lightening the skin, although no realstudy of its effectiveness has been carried out. Now, the Inventor foundthat the activity of the compositions according to the invention onhyperpigmentations of the freckle or chloasma type was considerablyenhanced when a preparation based on silver birch sap was combinedtherewith.

The excipients used in the production of the preparations according tothe invention may be very varied, and will be chosen in accordance withthe type of preparation which it is desired to obtain: milk, lotion,cream, gel, ointment, suncream, make-up foundation, body milk, and thelike.

Regular use of the preparations for the regulation of cutaneouspigmentation according to the invention makes it possible to removegradually pigmentation defects and to obtain a uniform skin colouring,and exhibits none of the disadvantages of the preparations of the priorart, in particular those based on hydroquinone. On the contrary, thepreparations according to the invention are perfectly tolerated, and canbe used over long periods, or even preventively, without any particularprecaution for their use being necessary.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be better understood with the aid of theadditional description which follows, which makes reference to examplesof the preparation and use of the depigmenting compounds according tothe invention.

It goes without saying, however, that these examples are given solely byway of illustration of the subject of the invention, of which they in noway constitute a limitation.

EXAMPLE 1

Production of an Aqueous-Alcoholic Extract from Leaves of Eclipta alba

250 g of Eclipta alba leaves are extracted, by maceration over 48 hours,in 1000 g of 70° strength ethanol in the presence of 2% of acetic acid.After filtration, the solution is concentrated by evaporation to 1/3 ofits initial volume.

This concentrated solution contains, per 100 g, 9 g ofdemethylwedelolactone and 6 g of wedelolactone.

EXAMPLE 2

Production of an Extract of Betula alba

20 g of silver birch sap are dissolved in 100 g of alcohol at 30° C.

EXAMPLE 3 Preparation of Cosmetic Compositions According to theInvention

    ______________________________________                                        A)    LIQUID CREAM                                                                  Liquid paraffin        8 g                                                    Perhydrosqualene       5 g                                                    Tefose 2561 (GATTEFOSSE)                                                                             10 g                                                   Arlamol HD (ICI)       6 g                                                    Arlamol D4 (ICI)       2 g                                                    Carbopol 940 (POLYPLASTIC)                                                                           0.3 g                                                  Eclipta alba (concentrated extract)                                                                  5 g                                                    Methyl para-hydroxybenzoate                                                                          0.02 g                                                 Propyl para-hydroxybenzoate                                                                          0.01 g                                                 Triethanolamine        0.3 g                                                  Ensolex filter 8021 (MERCK)                                                                          2 g                                                    Water                  QS 100 g                                         B)    THICK CREAM                                                                   Liquid paraffin        8 g                                                    Perhydrosqualene       5 g                                                    Tefose 2561 (GATTEFOSSE)                                                                             10 g                                                   Arlamol HD (ICI)       6 g                                                    Arlamol D4 (ICI)       2 g                                                    Carbopol 940 (POLYPLASTIC)                                                                           0.3 g                                                  Eclipta alba (concentrated extract)                                                                  15 g                                                   Betula alba (extract)  5 g                                                    Triethanolamine        0.3 g                                                  Methyl para-hydroxybenzoate                                                                          0.02 g                                                 Propyl para-hydroxybenzoate                                                                          0.01 g                                                 Water                  QS 100 g                                         ______________________________________                                    

C) PREPARATION PROCESS

I) Disperse the Carbopol in 2/3 of the total quantity of water. Allow toswell;

II) Weigh and place the liquid paraffin, perhydrosqualene, Tefose andArlamol HD on a water bath to dissolve;

III) Weigh the active ingredients (extract of Eclipta alba and/orextract of Betula alba), dissolve therein the methyl and propylpara-hydroxybenzoates;

IV) Weigh the triethanolamine and dissolve it in the remaining 1/3 ofwater;

V) Weigh the Arlamol D4;

After bringing the mixtures I) and II) to 90° C., mix with aturbo-mixer.

At 40° C. add the mixture III), then the Arlamol D4, and then neutralizeby adding the mixture IV).

    ______________________________________                                        D)     GEL                                                                           Carbopol 940            0.5%                                                  Triethanolamine         0.5%                                                  Eclipta alba (concentrated extract)                                                                   10%                                                   Water                   QS 100                                         ______________________________________                                    

EXAMPLE 4

Use of the Cosmetic Compositions according to the Invention

An experiment was carried out on 3 subjects having a chloasma, 2subjects having freckles, 4 subjects having hyperpigmentation related toacne scars and 3 subjects having a senile lentigo. The formulationdescribed in Example 3-B, with the exception of the extract of Betulaalba, was applied twice daily to the regions to be treated, for 2months.

No particular sun protection was used during the treatment.

The results are as follows:

In the subjects having an hyperpigmentation related to scars, as well asin those having a senile lentigo, an attenuation of the blemishes and aunification of the skin colour is observed from the third week. At theend of two months of treatment, the hyperpigmentation related to scarshas virtually disappeared in 3 of the 4 subjects, and is very stronglyattenuated in the fourth. The lentigo blemishes are very attenuated andthe skin coloration is uniform in the 3 subjects treated.

In the subjects having freckles and those having a chloasma, a slightattenuation is observed at the end of the two months of treatment. Thetreatment is continued for 2 months by the subjects, using the completeformulation of Example 3-B (that is to say, comprising the extract ofBetula alba).

At the end of these 2 additional months of treatment, a very clearattenuation of the chloasma is observed in the 3 subjects treated, andeven an almost total disappearance in one of them, and a significantattenuation of the freckles (visible uniformity of the complexion) inthe 2 subjects concerned.

I claim:
 1. A method for regulating cutaneous pigmentation comprisingapplying to the skin of a patient in need thereof a compositioncomprising as an active ingredient an effective amount to regulatepigment of a compound selected from the group consisting ofwedelolactone, demethylwedelolactone, and mixtures thereof.
 2. Themethod according to claim 1 wherein said active ingredient is selectedfrom the group consisting of between 0.1 and 15% by weight ofwedelolactone, between 0.1 and 15% by weight of demethylwedelolactone,and 0.1 and 15% by weight of wedelolactone and between 0.1 and 15% byweight of demethylwedelolactone.
 3. The method according to claim 1wherein said active ingredient is present in the form of an aqueousalcoholic plant extract which is rich in wedelolactone,demethylwedelolactone, or mixtures thereof.
 4. The method according toclaim 3 wherein said active ingredient is present in the form of anaqueous alcoholic extract obtained from leaves of Eclipta alba.
 5. Themethod according to claim 4 wherein said compositions comprise from 1 to25% of an aqueous alcoholic extract of leaves of Eclipta alba.
 6. Themethod according to claim 1 wherein said composition further includes anaqueous alcoholic extract of Betula alba.
 7. The method according toclaim 6 wherein said active ingredient is present in the form of anaqueous alcoholic plant extract which is rich in wedelolactone,demethylwedelolactone, or mixtures thereof.
 8. The method according toclaim 7 wherein said active ingredient is present in the form of an ofan aqueous alcoholic extract obtained from leaves of Eclipta alba. 9.The method according to claim 8 wherein said compositions comprise from1 to 25% of an aqueous alcoholic extract of leaves of Eclipta alba. 10.The method according to claim 1 wherein said composition contains acosmetically acceptable excipient.
 11. The method according to claim 10wherein said cosmetically acceptable excipient is selected from thegroup consisting of milks, lotions, creams, gels, ointments, suncreens,makeup foundations, and body milks.